Please Identify this deficiency!!!

My grow is 28 days into flower. Growing 5 different strains.
1.Gupta Kush (65-70 days harvest window)
2.Critical (65-70 days)
3.Poon Tang Pie (65-70)
4.Skunk#1 (70-75)
5.White Widow (65-70 days)

They are all in 5 gal smart pots same medium used which is a mix of Fox Farm Ocean Forest 1.5 liter bag, Happy Frog 1 liter bag, Worm castings about 1/2 liter bag, Dolomitic Lime 2 cups, perlite for added drainage.

Ph run off is 6.9
Temps are mid 70s F, 23/24 C lights on High 60s F, 20/21 C lights off
Humidity is a constant 45 to 50%
600 Watts HPS about 18" to 20" above the canopy

3 of the 5 strains are the only ones that are exhibiting this deficiency. The White Widows are looking fine.

My previous grow with the same medium, pot size etc.. I did not see anything like this and had a great harvest. From research I have suggestions of light burn, magnesium deficiency and/or Zinc or sulphur . It appears to be an immobile nutrient as the whole plant(s) have this
leaf appearance throughout the plant.

I am feeding them with Earth Juice which is a very acidic nutrient and some suggest to bubble the mix for 48 hours to raise the ph but I have reached out to the manufacture of EJ and they say it's not necessary that the microbial life balances it out. As I stated my previous grow under the same conditions didn't experience any deficiencies. I also supplement with Liquid Seaweed and Kelp meal and follow the recommended feeding for all nutrients I water in and I water just plain Ph'd water every other watering adding about a Tbs of molasses. When I water the plants I never water more than 2 quarts and/or 1.89 liters usually every 3 days.

I am freaking pulling my hair out trying to figure this out. Could someone with superior skills on deficiencies please chime in and get me pointed in the right direction I sure would appreciate it. Pictured is a leaf I pulled off the Skunk#1 girl but it applies to the other two strains. As I already mentioned the White Widow don't have leaves like this, they look perfectly healthy. I have read that it could be the strain simulating the plants life cycle (Picture Autumn/Fall conditions how the leaves change colors) but this early into flowering I doubt it total speculation at this point.

Thanks in advance and if there is any info I left out please let me know and I will reply in a very timely manner as I am on here quite a bit.

Thank you

Are you pHing the water/nutes you’re watering with?

Vanilla Phoenix said:

Are you pHing the water/nutes you’re watering with?

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Only when I water with plain water. Not when I mix the Earth Juice, liquid seaweed nutes. I mean I have done a ph soil run off test and the reading is in range. Blue Lab meter. I am positive that when I water with nutes that the ph going in is very acidic. Probably in the high 4s. What has me scratching my head is that this same routine on my last grow and no deficiencies. The only difference in this grow is applying molasses watered in and kelp meal top dressed about a Tbs and 1/2 each 5 gal smart pot.

Mix the nutrients and then pH to 6.5. I have used Earth Juice products on and off since the 90's and you definitely have to raise the pH after mixing the nutrients. I use silica to raise the pH.

All I can say is from my experiences. And I used to grow without pHing my nutes cause everyone kept saying about the soil buffering it...yada yada. I had all kinda deficiencies show up. Some grows had leaf spots, some grows yellowing, some grows went better than others. The problems always started around week 2 to 4 of bloom.

I then got sick of it and said to hell with it, and started pHing my nutes just to make sure. Haven’t had a problem since!

I came to the conclusion that the buffering effect of the soil was running out around the beginning of bloom, causing pH related problems. The way soil works, is if your soil pH is say 6.9, and you water with a pH of 6.5....the day you water, the roots are seeing 6.5 As the soil dries out, the pH swings back to 6.9, hitting everything between 6.5-6.9. This is what you want. This is one of the things that makes soil so forgiving.

When the pH buffer in your soil is fresh and new, even if you water with a pH of 4.0, your roots are seeing what your soil pH is, not the 4.0 But as the buffer weakens as the grow continues, it starts to get more persuaded by the solution you are watering with.

I bet if you start pHing everything going in, your problems would disappear like mine did. I’ve always used Foxfarm soils too, for the record.

Now, I’m no master gardener by any means. All of what I just wrote is my experience in what I’ve learned in the 20 years I’ve been growing.

Lester Beans said:

Mix the nutrients and then pH to 6.5. I have used Earth Juice products on and off since the 90's and you definitely have to raise the pH after mixing the nutrients. I use silica to raise the pH.

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It's great to hear from one that has experience with the same nutrient line! Thank you, and I have Silica on hand. I will start applying it to my nutes. I will just play with the amount I add to adjust the ph. Start small work my way up till I hit the sweet spot.

Thank you

Vanilla Phoenix said:

All I can say is from my experiences. And I used to grow without pHing my nutes cause everyone kept saying about the soil buffering it...yada yada. I had all kinda deficiencies show up. Some grows had leaf spots, some grows yellowing, some grows went better than others. The problems always started around week 2 to 4 of bloom.

I then got sick of it and said to hell with it, and started pHing my nutes just to make sure. Haven’t had a problem since!

I came to the conclusion that the buffering effect of the soil was running out around the beginning of bloom, causing pH related problems. The way soil works, is if your soil pH is say 6.9, and you water with a pH of 6.5....the day you water, the roots are seeing 6.5 As the soil dries out, the pH swings back to 6.9, hitting everything between 6.5-6.9. This is what you want. This is one of the things that makes soil so forgiving.

When the pH buffer in your soil is fresh and new, even if you water with a pH of 4.0, your roots are seeing what your soil pH is, not the 4.0 But as the buffer weakens as the grow continues, it starts to get more persuaded by the solution you are watering with.

I bet if you start pHing everything going in, your problems would disappear like mine did. I’ve always used Foxfarm soils too, for the record.

Now, I’m no master gardener by any means. All of what I just wrote is my experience in what I’ve learned in the 20 years I’ve been growing.

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Man bro makes total sense. I added 2 cups of the dolomite lime to a mix of 3 liters worth of medium it worked on my previous grow without incident why aren't the widows having a reaction I am in total agreement with you as far as pHing and will start watering in everything phed to 6.5. I respect your tenure with Cannabis and I appreciate your time to write out what you did. Excellent man! Thank you.... I guess certain strains are more sensitive and demanding than others. Did you notice after stabilizing your ph a reverse in the appearance of the affected area of the plant or did you just focus on new growth?

Thanks again

Hello. Listen ... I think 2 cups of Dolomite to 3 litres of 'mix' is excessive. How excessive will depend on the quality of the Dolomite. Excessive Dolomite/alkaline soil will cause leaves to go like yr pictures.
Have you pH'd the soil? Never mind measuring the runoff. Buy a Soil pH Test Kit. They're cheap.
If excess Dolomite is the cause you will have a hard time correcting the pH of your soil. I 'm sorry to say it is difficult to get soil pH 'down'.

Traceofvenom said:

Man bro makes total sense. I added 2 cups of the dolomite lime to a mix of 3 liters worth of medium it worked on my previous grow without incident why aren't the widows having a reaction I am in total agreement with you as far as pHing and will start watering in everything phed to 6.5. I respect your tenure with Cannabis and I appreciate your time to write out what you did. Excellent man! Thank you.... I guess certain strains are more sensitive and demanding than others. Did you notice after stabilizing your ph a reverse in the appearance of the affected area of the plant or did you just focus on new growth?

Thanks again

Click to expand...

That right there

I grow various strains at the same time and they don't all react the same way. Because of our restrictions (4 plants) one has to do what one needs to do when growing medicine. It is a PITA (growing 2-4 delta strains at the same time). Down the road, in a grow or two, I will be able to grow single strains at a time. Looking forward to that day

Teddybrae said:

Hello. Listen ... I think 2 cups of Dolomite to 3 litres of 'mix' is excessive. How excessive will depend on the quality of the Dolomite. Excessive Dolomite/alkaline soil will cause leaves to go like yr pictures.
Have you pH'd the soil? Never mind measuring the runoff. Buy a Soil pH Test Kit. They're cheap.
If excess Dolomite is the cause you will have a hard time correcting the pH of your soil. I 'm sorry to say it is difficult to get soil pH 'down'.

Click to expand...

Yo Teddybrae,

I misquoted I meant 3 cubic feet of medium.

I added 2 cups of Dolomite lime to 3 cubic feet of medium which is a little over 20 dry gallons of medium. Which equals about 5.3 Tbs per 5 gallons of medium which is roughly 1 Tbs per gallon.
I did buy one of those cheap soil kits from Lowes that test the NPK and the Ph. The results showed very acidic for the ph. I personally think the test kit is inaccurate. What can one expect from a $10 kit. With respect to the run off I basically went down the side of the smart pot about 1/2 way down and grabbed a good handful of medium then put it in a glass and poured about a 5 to 1 ratio of neutral phd water of 7.0 and stirred. I let the medium settle to the bottom about 30 minutes then tested the Ph with my meter and it was 6.9 so I am confident that I didn't put excess dolomite lime in when I mixed everything together.
I am leaning towards Vanilla Phoenix theory that the buffering has run its' course and that I need to be Phing my nute mix before watering in this also recommended by Lester Beans and I also think certain strains are more sensitive and needy than others. As I stated the White Widows look perfectly healthy but the other strains are exhibiting the deficiency. So from here out nothing gets watered in until it is Phd to 6.5. Hopefully, I am not to late on this go around. Time will tell.

Peace

Switcher56 said:

That right there
Down the road, in a grow or two, I will be able to grow single strains at a time. Looking forward to that day

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This is what I am wanting to eventually get to. I am growing different strains to find that one that resinates perfectly for my specific needs. Once I find it I will make a mother and will be able to dial it in and the rest will be history.

Peace

Epsom salt is good for both magnesium and sulfur deficiency.

Traceofvenom said:

I am positive that when I water with nutes that the ph going in is very acidic. Probably in the high 4s. What has me scratching my head is that this same routine on my last grow and no deficiencies. The only difference in this grow is applying molasses watered in and kelp meal top dressed about a Tbs and 1/2 each 5 gal smart pot.

Click to expand...

I have to say I never had good experiences with feeding molasses directly, without some kind of fermentation process.

If the pH is that low, the molasses may have gone to feeding the wrong fungi/bacteria, the kinds that thrive in anaerobic conditions and like/create a pH of 4.0.

It could be a mobile nutrient deficiency like not enough magnesium or Potassium.

However it could also be a nutrient lockout, because of

a) low pH, which locks out mobile nutrients
b) fungal infection of the roots, which also blocks nutrient absorption through the roots

Basically raw organic materials like molasses or kelp are great for making teas, turning into compost or supersoil, or my favorite, add a few drops of water and create a stiff paste that you don't water in and put on the top of the soil, before you cover it with a soft carbon based mulch like hemp bedding or chopped straw. Other benefits of adding solid nutrients to the soil like that, are: you don't have to flush if you add too much; heat from decomposition is easily dispersed in the air and doesn't burn the roots; you can add whatever you like whenever you like and remove it.

SOLUTION

1. Check if there is something wrong with the roots.
2. Smell the affected leaves. Do they smell moldy/dank instead of fresh and green? If so, that's what's going on.
3. If this is an organic grow, shoot for a pH of 7.0 or a little higher, which is best for microbes.
4. Check the runoff's EC and pH. If they're high, then there are too many nutrients in the soil or the roots have been burnt.

5. If the pH of the runoff and nutrients are right (around 7.0) and there is no high EC to the runoff... the plants are hungry and need a good feeding of mid-bloom food and magnesium. At this stage, you could add two or more inches of soil to the top of the pot, after feeding extra P, K, Si, S, Ca and trace elements.

Anaerobic fungi grow at a pH of 4.0, so the way to get rid of them is to raise the pH to 7.0 or so. Dead roots can be broken down with a few drops of enzymes. Don't use the recommended amount, because they can release a lot of nutrients into the media very quickly and burn the plant.

Happened to a friend by time adjusted everything sadly to late. Thinking it was super buildup in soil

troutman said:

Epsom salt is good for both magnesium and sulfur deficiency.

Click to expand...

Yeah, I have some Epsom but after further research I decided to add Kelp meal instead as it has Mag/Cal/Sulfur and a bunch of other goodies plus it's organic. However, I am considering using it as a foliar application.

Peace

TanzanianMagic said:

I have to say I never had good experiences with feeding molasses directly, without some kind of fermentation process.

If the pH is that low, the molasses may have gone to feeding the wrong fungi/bacteria, the kinds that thrive in anaerobic conditions and like/create a pH of 4.0.

It could be a mobile nutrient deficiency like not enough magnesium or Potassium.

However it could also be a nutrient lockout, because of

a) low pH, which locks out mobile nutrients
b) fungal infection of the roots, which also blocks nutrient absorption through the roots

Basically raw organic materials like molasses or kelp are great for making teas, turning into compost or supersoil, or my favorite, add a few drops of water and create a stiff paste that you don't water in and put on the top of the soil, before you cover it with a soft carbon based mulch like hemp bedding or chopped straw. Other benefits of adding solid nutrients to the soil like that, are: you don't have to flush if you add too much; heat from decomposition is easily dispersed in the air and doesn't burn the roots; you can add whatever you like whenever you like and remove it.

SOLUTION

1. Check if there is something wrong with the roots.
2. Smell the affected leaves. Do they smell moldy/dank instead of fresh and green? If so, that's what's going on.
3. If this is an organic grow, shoot for a pH of 7.0 or a little higher, which is best for microbes.
4. Check the runoff's EC and pH. If they're high, then there are too many nutrients in the soil or the roots have been burnt.

5. If the pH of the runoff and nutrients are right (around 7.0) and there is no high EC to the runoff... the plants are hungry and need a good feeding of mid-bloom food and magnesium. At this stage, you could add two or more inches of soil to the top of the pot, after feeding extra P, Si, S, Ca and trace elements.

Anaerobic fungi grow at a pH of 4.0, so the way to get rid of them is to raise the pH to 7.0 or so. Dead roots can be broken down with a few drops of enzymes. Don't use the recommended amount, because they can release a lot of nutrients into the media very quickly and burn the plant.

Click to expand...

YO TanzanianMagic,

Thanks for taking the time to reply. Great info! If you go back through the thread I addressed a lot of what you said. My ph run off is pretty neutral at 6.9 but I didn't check the EC/PPM so I will do that this evening when the lights kick on what is an ideal range on PPM or EC I am looking for. I didn't even think about adding another 2 to 3 inches of fresh soil to the top. Excellent idea!

Peace